This application is based upon and claims the benefit of priority from the prior Japanese Patent Applications No. 11-250515, filed Sep. 3, 1999; and No. 2000-151422, filed May 23, 2000, the entire contents of which are incorporated herein by reference.
The present invention relates to a motor control circuit and a control system comprising a main control section and unit control sections connected to said main control section.
Conventionally, a number of pulse motors are provided in a medium conveying apparatus for conveying a medium such as paper or the like in order to separate and transfer the medium and for other purposes.
To control these motors, motor control pulses are generated by means of the CPU of the main control section, are transmitted to the unit control sections via serial circuits and are supplied to the pulse motors.
However, when motor control pulses are generated by the CPU as in the above-described prior art, the particular CPU is overloaded. Further, since the pulses are transmitted via the serial circuits, the data thereof become large in amount.
The present invention has been made in consideration of the above-described problems. The first object of the invention is to make it possible to set and operate the pulse generation circuit via serial circuits, and to eliminate the necessity of transmitting the driving pulses via the serial circuits, by providing a pulse generation circuit on the unit control section side. The second object of the invention is to make it possible to diagnose the states of operation by obtaining the count of really generated pulses after the operation of the pulse generation circuit. The third object of the invention is to make it possible to accelerate and decelerate the pulse rate linearly and to set the rate of each pulse partially. The fourth object of the invention is to provide a motor control circuit that can not only reduce the cost but also accomplish complex motor control and a control system that uses the same.
In order to attain the above-described objects, in the first embodiment of the present invention, a motor control circuit for use in a control system a main control section and unit control section connected to the main control section controlling the circuit of the pulse motor, the unit control section comprising: pulse generation means for generating control pulses of desired frequency by dividing the basic clock by a predetermined count value; pulse count means for counting the control pulses; first means for holding at least the information concerning the upper and lower limits of the speed: second means for holding at least the information concerning the acceleration and deceleration speeds; speed change means for increasing or decreasing the speed data gradually by counting the count of the pulse count means from the lower limit to the upper limit of the speed held in the first means, in accordance with a value corresponding to the acceleration or deceleration speed held in the second means; and means for instructing the rewriting the values held in the first and second means and the starting and stopping of the operation, wherein the rotation of the pulse motor is controlled in accordance with the commands supplied from the main control section.
In the second embodiment of the present invention, a control system including a main control section and unit control section connected to the main control section and having a plurality of motor control circuits, the motor control circuit comprising: means for generating a basic clock; pulse generation means for generating control pulses of desired frequency by dividing the basic clock by a predetermined count value; pulse count means for counting the control pulses; rate data conversion means for converting the speed data into a count value used in the pulse generation means; first means for holding at least the information concerning the upper and lower limits of the speed; second means for holding at least the information concerning the acceleration and deceleration speeds; and means for increasing or decreasing the speed data gradually by counting the count of the pulse count means from the lower limit to the upper limit of the speed held in the first means, in accordance with a value corresponding to the acceleration or deceleration speed held in the second means, wherein the rate data conversion means is shared by the plurality of motor control circuits by setting different operation clocks in the plurality of motor control circuits.
In the third embodiment of the present invention, a control system including a main control section and unit control section connected to the main control section, the main control section comprising means for holding a predetermined command for controlling the operation of the unit control section, and the unit control section comprising: motor control circuit comprising; means for generating a basic clock; pulse generation means for generating control pulses of desired frequency by dividing the basic clock by a predetermined count value; pulse count means for counting the control pulses; means for converting the speed data into a count value used in the pulse generation means; first means for holding at least the information concerning the upper and lower limits of the speed; second means for holding at least the information concerning the acceleration and deceleration speeds; speed change means for increasing or decreasing the speed data gradually by counting the count of the pulse count means from the lower to the upper limit of the speed held in the first means, in accordance with a value corresponding to acceleration or deceleration speed held in the second means; and command run means for giving the instructions of rewriting the values held in the first and second means and of starting and stopping the operation corresponding to a predetermined command from the main control section.
In the fourth embodiment of the present invention, a motor control circuit including a main control section and unit control section connected to the main control section and controlling the circuit of the pulse motor is provided, wherein the unit control section have pulse generator obtaining control pulses of desired frequency by dividing the basic clock by a predetermined count value, pulse counter counting the control pulses, first storage holding at least the information concerning the upper and lower limits of the speed, second storage holding at least the information concerning the acceleration and deceleration speeds, speed changer increasing or decreasing the speed data gradually by counting the count of the pulse counter from the lower limit to the upper limit of the speed held in the first storage, in accordance with a value corresponding to the acceleration or deceleration speed held in the second storage, and instructor to rewriting the values held in the first and second storage and to starting and stopping the operation, wherein the rotation of the pulse motor is controlled corresponding to the commands from the main control section.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.